How do you solve 1/(t+1) = (2x-6)/(3x+8)1t+1=2x63x+8?

1 Answer
Jun 24, 2015

t = 1/2 + 17/(2x-6)t=12+172x6

with exclusion x != -8/3x83

x = 17/(2t-1)+3x=172t1+3

with exclusion t != -1t1

Explanation:

First note that the values x = -8/3x=83 and t = -1t=1 cause division by 00, so are excluded values.

Multiply both sides of the equation by (3x + 8)(3x+8) to get:

(3x+8)/(t+1) = 2x-63x+8t+1=2x6

Multiply both sides of this equation by (t+1)(t+1) to get:

3x+8 = (2x-6)(t+1)3x+8=(2x6)(t+1)

=(2x-6)t + (2x - 6)=(2x6)t+(2x6)

Subtract (2x-6)(2x6) from both sides to get:

(2x-6)t = (3x+8)-(2x-6)(2x6)t=(3x+8)(2x6)

=3x + 8 - 2x + 6=3x+82x+6

=3x - 2x + 8 + 6=3x2x+8+6

=(3-2)x+14=(32)x+14

=x+14=x+14

Divide both ends by (2x-6)(2x6) to get:

t = (x+14)/(2x-6)t=x+142x6

=(x-3+17)/(2(x-3))=x3+172(x3)

=(x-3)/(2(x-3))+17/(2(x-3))=x32(x3)+172(x3)

=1/2+17/(2(x-3))=12+172(x3)

=1/2+17/(2x-6)=12+172x6

So:

color(red)(t = 1/2 + 17/(2x-6))t=12+172x6

To find xx in terms of tt, first subtract 1/212 from both sides to get:

t - 1/2 = 17/(2x-6)t12=172x6

Multiply both sides by 22 to get:

2t-1 = 17/(x-3)2t1=17x3

Multiply both sides by (x-3)(x3) and divide both sides by (2t-1)(2t1) to get:

x-3 = 17/(2t-1)x3=172t1

Add 33 to both sides to get:

color(red)(x = 17/(2t-1)+3)x=172t1+3